/*
 * Copyright 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package de.google.android.apps.iosched.io;

import static org.xmlpull.v1.XmlPullParser.END_DOCUMENT;
import static org.xmlpull.v1.XmlPullParser.END_TAG;
import static org.xmlpull.v1.XmlPullParser.START_TAG;
import static org.xmlpull.v1.XmlPullParser.TEXT;

import de.aformatik.android.apps.jfs.R;
import de.google.android.apps.iosched.provider.ScheduleContract;
import de.google.android.apps.iosched.provider.ScheduleContract.Rooms;
import de.google.android.apps.iosched.util.Lists;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import android.content.ContentProviderOperation;
import android.content.ContentResolver;

import java.io.IOException;
import java.util.ArrayList;

/**
 * Handle a local {@link XmlPullParser} that defines a set of {@link Rooms}
 * entries. Usually loaded from {@link R.xml} resources.
 */
public class LocalRoomsHandler extends XmlHandler
{
	public LocalRoomsHandler()
	{
		super(ScheduleContract.CONTENT_AUTHORITY);
	}

	@Override
	public ArrayList<ContentProviderOperation> parse(XmlPullParser parser, ContentResolver resolver)
			throws XmlPullParserException, IOException
	{
		final ArrayList<ContentProviderOperation> batch = Lists.newArrayList();

		int type;
		
		while ((type = parser.next()) != END_DOCUMENT)
		{
			if (type == START_TAG && Tags.ROOM.equals(parser.getName()))
			{
				parseRoom(parser, batch, resolver);
			}
		}

		return batch;
	}

	/**
	 * Parse a given {@link Rooms} entry, building
	 * {@link ContentProviderOperation} to define it locally.
	 */
	private static void parseRoom(XmlPullParser parser, ArrayList<ContentProviderOperation> batch,
			ContentResolver resolver) throws XmlPullParserException, IOException
	{
		final int depth = parser.getDepth();	
		
		ContentProviderOperation.Builder builder = ContentProviderOperation.newInsert(Rooms.CONTENT_URI);
		String tag = null;
		int type;
		
		while (((type = parser.next()) != END_TAG || parser.getDepth() > depth) && type != END_DOCUMENT)
		{
			if (type == START_TAG)
			{
				tag = parser.getName();
			}
			else if (type == END_TAG)
			{
				tag = null;
			}
			else if (type == TEXT)
			{
				final String text = parser.getText();
				
				if (Tags.ID.equals(tag))
				{
					builder.withValue(Rooms.ROOM_ID, text);
				}
				else if (Tags.NAME.equals(tag))
				{
					builder.withValue(Rooms.ROOM_NAME, text);
				}
				else if (Tags.FLOOR.equals(tag))
				{
					builder.withValue(Rooms.ROOM_FLOOR, text);
				}
			}
		}

		batch.add(builder.build());
	}

	/** XML tags expected from local source. */
	private interface Tags
	{
		String ROOM = "room";
		String ID = "id";
		String NAME = "name";
		String FLOOR = "floor";
	}
}
